Tufted carpet is used as a floor covering in many commercial and residential facilities. Conventional tufted carpets comprise a primary backing with yarn tufts in the form of cut or uncut loops extending upwardly from the backing and forming a pile surface. Typically, the yarn is inserted into the backing by tufting needles and maintained permanently in place by a heat-sensitive coating composition (e.g., a thermoplastic resin) applied to the back surface of the primary backing. When heat is applied to the composition, the pile yarns are fused to the primary backing creating an integral tufted carpet. See, for example, U.S. Pat. No. 3,695,987 to Wisotzky et al.
Conventional tufted carpets may also include a secondary backing bonded to the primary backing. The secondary backing provides extra padding to the carpet, absorbs noise, adds dimensional stability and often functions as a heat insulator. The secondary backing can be formed from natural fibers (e.g., jute), or synthetic fibers (e.g., polypropylene), and can be a woven or non-woven material. The secondary backing can also be a foam composition comprised of urethane polymers.
The secondary backing may be bonded to the primary backing via hot-melt adhesives. See, for example, U.S. Pat. No. 3,390,035 to Sands. Alternatively, the same coating composition used to secure the tufted yarns to the primary backing may also function as an adhesive layer for bonding the secondary backing to the primary backing. See, for example, U.S. Pat. No. 4,808,459 to Smith et al.
Historically, the pile face of conventional tufted carpets was comprised of only single color yarns. However, as interior styling has become more fashionable, particularly for large commercial facilities, there has been an increase in demand for visually pleasing tufted carpets comprising various colors, designs, and patterns. One method of creating patterns and designs in tufted carpet is to insert yarns of different colors into the primary backing during manufacturing of the carpet. See, for example, U.S. Pat. No. 4,877,669 to Endrenyi, Jr. et al. See also, U.S. Pat. No. 5,198,277 to Hamilton et al. Another method involves printing different colors, patterns or designs directly on the pile face of a manufactured carpet. Unfortunately, this is an expensive post-manufacturing process and, thus, is not a very desirable method.
Yet another technique for producing visually pleasing tufted carpet involves the use of decorative inlays. In general, this technique includes the steps of cutting a carpet to create an opening having a decorative shape, placing an inlay in the opening of the carpet, and securing the inlay to the carpet. See, for example, U.S. Pat. No. 1,947,152 to Clark, U.S. Pat. No. 2,012,929 to Knowland, and U.S. Pat. No. 2,245,202 to Krasno. This is typically done by the customer or consumer, and does not permit large scale production of carpet.
Unfortunately, the existing methods of making inlaid carpet have various disadvantages. Typically, an inlay is secured within a carpet by either applying a hot melt adhesive to the abutting edges of the inlay and carpet or by applying a patch over the adjoining edges of the backing of the inlay and carpet. Unfortunately, a joint between an inlay and carpet resulting from either of these methods may be susceptible to tension when the carpet is stretched, which may result in the inlay becoming detached from the carpet. Stretching may occur during manufacturing when the carpet is convolutely wound in rolled form and also during installation. Ordinary usage from foot traffic also has the tendency to stretch the joint between the inlay and carpet, causing the inlay to become dislocated. Furthermore, none of the known methods of securing an inlay within a pile carpet completely eliminate the presence of an unsightly seam along the abutting edges of the carpet and inlay.